With advancement in technology, communication devices with multiple antennas have been widely used to receive signals propagating through multiple paths, providing antenna diversity, also known as space diversity. Providing the antenna diversity facilitates in improving the bit error rate (BER) quality and reliability of a wireless link. Additionally, multiple antennas offer a receiver several observations of the same transmitted signal. For instance, each of the multiple antennas may experience a different interference environment. Thus, if one antenna is experiencing a deep fade, another antenna may receive a better signal. Further, such communication devices typically implement a multiple antenna equalizer (MAEQ) that equalizes samples of the signals received by each of the multiple antennas based on correlation properties of the received signals. Using the signals received by all the antennas allows the MAEQ to provide better noise reduction, higher gain, and better interference cancellation as compared to communication devices having only a single antenna.
However, in order to achieve the aforementioned advantages, the signals received by the multiple antennas need to be un-correlated, due to which the multiple antennas need to be separated by a particular distance. Separating the antennas by the particular distance, however, may not be always possible, for example, in handheld communication devices due to their small size.
Further, in situations where one or more of the antennas from amongst the multiple antennas becomes inactive, i.e., faulty or grounded, the particular antenna may not receive any signals and may accordingly generate only noise signals at its output. The MAEQ, in such a case, may not be able to identify that a particular antenna has become inactive and may include the noise signal as one of its input signals for equalizing, resulting in a higher bit error rate (BER), and thus, leading to a degradation in performance of the communication device.
In order to avoid aforementioned complexities, manufacturers may implement a single antenna equalizer (SAEQ) configured to equalize signals from only one of the multiple antennas or may simply provide the communications devices with only a single antenna. However, using either the single antenna or SAEQ with multiple antennas may degrade the performance of the communication devices as the SAEQ may not be able to provide interference suppression similar to the MAEQ.
Manufacturers of a communication device may thus need to decide upon a multiple antenna implementation for the communication device considering the benefits, such as high interference suppression, and limitations, such as increased cost and high BER in case of an antenna being rendered inactive. The SAEQ or the MAEQ is accordingly implemented in the communication device depending upon whether the communication device has a single antenna implementation or a multiple antenna implementation.